Metal feeding mechanism for grid casting machines



-E='@b. 2, 1932 A. D. LUND Lwmm METAL FEEDING MECHANISM FOR GRID CASTING MACHINES Original Filed Aug. 24, 1928 2 Sheets-Sheet l .INVENTOR ARTHUR D.Lu/v0 ATTORNEY 5* tmb. 2, R932. A. LUND L E METAL FEEDING MECHANISM FOR G RID CASTING MACHINES Original Filed Aug. 24, 1928 2 Sheets-Sheet 2 INVENTOR J ARTHUR D. Lu/vo ATTORN EY Patented Feb. 2, 1932 UNITED STATES PATENT OFFICE ARTHUR D. LUND, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO ALCET ELECTRO-PROD- UCTS CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE METAL FEEDING MECHANISM FOR GRID CASTING MACHINES Original application filed August 24, 1928, Serial No. 301,830. Divided andthis application filed August 17,

1929. Serial No. 386,555.

This invention relates to metal feeding mechanisms for casting machines, and the pri-' molds. A further object is to provide a feed pump that will operate in a submerged position in a mass of molten metal in the melting chamber, and-will do so without in any way accumulating dross or litharge which would otherwise have a tendency to retard'and possibly stop the pump action, this being particularly true in a machine, such as a battery grid casting machine, where the metal consists principally of lead. The present application is a division of my co-pending patent application, Ser. N 0. 301,830, filed August 24, 1928, for grid casting machine, and as to some subject matter is a continuation in part of my co-pending application, Ser. No. 213,575, filed August 17, 1927, for grid casting machine, the last named application having sincebeen issued as Patent, N 0. 1,811,143, granted June 23rd, 1931.

In the accompanying drawings: Fig. 1 is an elevation, partly in .section, showing an application of the present invention to a casting machine.

Fig. 2 is a detail sectional view as on the line 22 in Fig. 1.

Fig. 3 is a detail plan elevation of the valve and valve actuator mechanism of the pump,

' as seen substantially on the line 33 in Fig. 1.

Fig. 4 is a detail plan view of the pump chamber and attached spout, with adjacent parts removed.

Fig. 5 is a detail elevation, partly in section,

as on the line 55 in Fig. 4.

Referring to the drawings more particularly and. by reference characters, 6 designates the main frame of a casting machine having a furnace box 7, lined with brick 8. The metal melting chamber or pot 9 is disposed within the upper p'art of the furnace box and has a flange 10 sup orted thereon, thus confining the space between the chamber and box so that-the burner (not shown) will effectively heat the metal chamber to melt the metal therein. The molten metal in the chamber is designated by the numeral 11 and is normally retained at about thelevel shown in Fig. 1.

The metal feeding or pumping devices, of which two are employed, as shown in Fig. 1, are in part suspended into the melting pot 9, and are carried by the cross beam 12 of a frame having legs 13 that pivotally connect,

as at 14, to the main frame 6, so thatthepumping units may be swung or tilted up clear of the molten metal when so desired.

. Each of the pump units comprises a chamber 15 integrally formed at the lower end of a leg or bracket 16 which is secured, at its upper end to the beam 12. A displacement piston 17 operates in the pump chamber 15, and its downward movement operaates to force a predetermined amount of lead (or other metal) from the chamber out through a spout 18 and through a nozzle 19 into the empty molds. The pistons or plungers 17 are vertically reciprocated by a mechanism, which, as with the mold units, are not here described in View of the more complete disclosures thereof as found in my application, Ser. No. 301,830.

Upon the up stroke of each piston or plunger 17 a valve 20 is opened, permitting the chamber 15 to again fill up, it being understood that the level of the metal in the pot 9 is always above the valve ports 20.

The lead level with respect to the pump 1517.is indicated in Figs. 1 and 2, and it is of considerable importance that it is so located, for reasons that will presently appear. The piston 17 operates through a packing gland sleeve 21, secured as at 22, and through a smaller sleeve 23 screwing into the sleeve 21. The openings in these sleeves are suliiciently largeto freely receive the plunger 17 and preferably do not contact with it at all, their sole object being to hold a packing composition,-as at 24, and to hold a lubricant, such as powdered graphite, as at 25. A heavy bearing member 26 forms the primary bearing support and guide for the plunger 17. The material 24 is of course tightly packed about the plunger by screwingdown of the sleeve 23, and its sole purpose is to keep air out of the pump chamber and also to wipe the lead off of the rising piston. By this construction, it Will be noted, all possibility of litharge forming on the piston is entirely eliminated, as no part of the piston contacting with the lead comes in contact with the atmosphere, at least until it is first entirely wiped clean.

It may here be noted that the pump chambers 15 are provided with valve control vents 27, through which the chambers may be drained when the feed mechanism is tilted to its raised or idle position.

The lead chamber valves 20 are opened and closed by the vertical reciprocating action of a pair of rods 28, guided,as at 29, at their lower ends, and in bearings 30 near their upper ends (Figs. 1 and 3). Springs 31, the tensions of which are regulated by adjustment nuts 32, tend to hold the rods 28 down with the valves closed. At their extreme upper ends the rods 28 are provided with collars 33 under which engage the bifurcated or fingered ends of the arm 34 of a lever which fulcrums as at 35 and has a rearwardly and upwardly projecting arm 36. This arm 36 is connected by a bar 37 to the upper arm 38 of a lever that fulcrums as at 39 and has a lower arm 40 :provided'with a roller 41 that travels on the face of a cam '42. A spring 43, acting upon the arm 34 to pull it down, tends to take all slack out of the joints and keeps the roller 41 in continuous working contact with the edge of thecam 42. The cam 42 is continuously rotated as by a mechanism as shown in application, Ser. No. 301,830, but it may here be stated that the parts are so proportioned and arranged that the valve 20 remains open during the travel of the roller 41 on the cam. surface extending from E to F, the valve closes from points F to G, remains closed until the roller reaches point H, and opens on the stroke from H to E. And these movements are all timed and synchronized with reference to the pump actuating mechanism, with a result that the valves remain closed during the down stroke of the pump pistons and for a moment thereafter, to prevent dripping from the nozzles 19, and then open and stay open during the major up stroke of the pistons, which is the chamber filling period, and this cycle is repeated for each casting operation.

It is understood that suitable modifications may be-made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims.

Having now therefore fully illustrated and described my invention, what I claim to benew and desire to protect by Letters Patent 1s:

1. In a casting .machine, a molten metal receptacle, a pump chamberdisposed within the receptacle and having an inlet port and a discharge spout, a displacement piston operative in the chamber, a packing box carried by the chamber for the piston, said box having an inclosed packing groove and an annular recess independent of and arranged above the groove to contain a lubricant.

/ 2. In a casting machine, a melting pot, a pump chamber therein and having a valved connection with the interior of the pot, a displacement piston operating in the pump chamber, a pair of relatively adjustable members forming an annular groove to receive and retain a packing about the piston, one of said members having a recess, adjacent the piston but independent of the packing groove, to contain a lubricant.

3. In a casting machine, a melting pot, a pump chamber therein and having a valved connection with the interior of the pot, a displacement piston operating in the pump chamber, and a pair of relatively adjustable members, one of which screws into the other to receive and adjustably secure a packing ring, one of said adjustable members being provided with a lubricant recess adjacent the piston but spaced from said packing ring.

4. A feed pump for a casting machine comprising a valve controlled chamber submergible in a mass of molten metal, a displacement piston operative in the chamber, a packing ring about the piston, and a gland in adjustablefl contact with the ring, said gland having a lubricant receiving recess adjacent the piston but spaced from the packing ring.

5. A feed pump for a casting machine comprising a valve controlled chamber submergible in a mass of molten metal, a displacement piston operative in the chamber, a packing ring about the piston, and a gland in adj ustable contact with the ring, said gland having an upwardly opening lubricant receiving recess about the piston, and said gland being disposed with the open end of said recess above the level of the mass of molten metal in the chamber.

6. A feed pump for a casting machine comprising a valve controlled chamber submergible in a mass of molten metal, a displacement piston operative in the chamber, a packing box carried by the chamber and disposed about the piston, and a gland extending and screwing into the packing box to confine the packing therein.

7. A feed pump for a casting machine comprising a valve controlled chamber submergible in a mass of molten metal, a displacement piston operative in the chamber, a packing box carried by the chamber and disposed about the piston, and a gland extending into the packing box to confine the packing therein, said gland having a lubricant retaining recess for providing the piston with lubricant at a point spaced from the packing.

8. In a casting machine having a molten metal pot, a support tiltably disposed above the pot, a bracket extending downwardly from the support, a pump chamber carried by the bracket for operation'in the pot, a displacement piston operative in the chamber and having guiding engagement with the support, and a cam actuated valve for the pump chamber;

Signed at Minneapolis, in the county of Hennepin and State of Minnesota, this th day of August, 1929.

'ARTHUR D. LUND. 

